diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2020-10-28 09:04:33 +0100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-11-19 14:50:14 +1100 |
| commit | a7223f5bfcaeade4a86d35263493bcda6c940891 (patch) | |
| tree | 49ebe9ce99cf355cff1d1c66d8f60c4189964b32 /arch/powerpc/kernel/paca.c | |
| parent | ffa1797040c5da391859a9556be7b735acbe1242 (diff) | |
powerpc: Avoid broken GCC __attribute__((optimize))
Commit 7053f80d9696 ("powerpc/64: Prevent stack protection in early
boot") introduced a couple of uses of __attribute__((optimize)) with
function scope, to disable the stack protector in some early boot
code.
Unfortunately, and this is documented in the GCC man pages [0],
overriding function attributes for optimization is broken, and is only
supported for debug scenarios, not for production: the problem appears
to be that setting GCC -f flags using this method will cause it to
forget about some or all other optimization settings that have been
applied.
So the only safe way to disable the stack protector is to disable it
for the entire source file.
[0] https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html
Fixes: 7053f80d9696 ("powerpc/64: Prevent stack protection in early boot")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
[mpe: Drop one remaining use of __nostackprotector, reported by snowpatch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201028080433.26799-1-ardb@kernel.org
Diffstat (limited to 'arch/powerpc/kernel/paca.c')
| -rw-r--r-- | arch/powerpc/kernel/paca.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c index 0ad15768d762..7f5aae3c387d 100644 --- a/arch/powerpc/kernel/paca.c +++ b/arch/powerpc/kernel/paca.c @@ -208,7 +208,7 @@ static struct rtas_args * __init new_rtas_args(int cpu, unsigned long limit) struct paca_struct **paca_ptrs __read_mostly; EXPORT_SYMBOL(paca_ptrs); -void __init __nostackprotector initialise_paca(struct paca_struct *new_paca, int cpu) +void __init initialise_paca(struct paca_struct *new_paca, int cpu) { #ifdef CONFIG_PPC_PSERIES new_paca->lppaca_ptr = NULL; @@ -241,7 +241,7 @@ void __init __nostackprotector initialise_paca(struct paca_struct *new_paca, int } /* Put the paca pointer into r13 and SPRG_PACA */ -void __nostackprotector setup_paca(struct paca_struct *new_paca) +void setup_paca(struct paca_struct *new_paca) { /* Setup r13 */ local_paca = new_paca; |